How to Change Garmin Vivofit 4 Battery (and Hack Capacity to Make Longer-Lasting)! - YouTube
Amazon.com: Garmin vívofit 4 activity tracker with 1+ year battery life and color display. Small/Medium, Black. 010-01847-00, 0.61 inches : Sports & Outdoors
vívofit Owner's Manual - Replacing the vívofit Device Batteries